Super fast but you'll need line-of-sight

In five years or so, Wi-Fi access points could carry data at rates 100 times faster than today using infrared light rather than other portions of the electromagnetic spectrum.

Researchers at Eindhoven University of Technology (TU/e) in the Netherlands have developed a way to use fiber optic cables, mounted with networking hardware in a room, to shine data directly to devices using harmless infrared light.

The researchers managed to achieve speeds of 42.8 Gbit/s over a distance of 2.5 metres (8.2 feet) with this technique. That's about 2,000 times faster than average Wi-Fi speeds in the Netherlands (~17.6 Mbit/s) and more than 100 times faster than top-tier Wi-Fi setups (~300 Mbit/s, although Wi-Fi networking speeds in the real world are highly variable).

Where current Wi-Fi systems typically operate at a frequency of 2.5 or 5 gigahertz, the infrared system works at frequencies about 50,000 times higher, around 200 terahertz, allowing for faster transmission of data.

The fiber optic cables – or light antennas – use a pair of gratings to refract light of different wavelengths at different angles, thereby changing the direction of the invisible illumination.

According to TU/e, other scientists have investigated infrared light as a networking medium, but their systems directed light beams using mirrors, which require active control and power, and can only handle one light beam per mirror.

LED lighting has also been explored but it has drawbacks – low bandwidth and broadcast rather than targeted transmission.

The approach developed by doctoral student Joanne Oh, as part of the BROWSE project run by TU/e professor Ton Koonen, involves direct transmission from access point to device. The researchers are still refining the mechanism by which endpoint devices, as they move, can be kept in contact with at least one radiating light beam.

They also have only tested the downloading of data; uploads during trials were handled using traditional radio signals. ®